If you are like most folks that own an automobile and drive it regularly for work, play or the innumerable other tasks that make up modern life chances are you rarely give your tires much thought unless they’re going to cost you: cost you money, when it is time to replace a worn out set, or cost you time and aggravation in case one goes flat on the road.
But failing to understand tires, how to choose and maintain them, could ultimately cost you your life, either on a daily commute or in the gravest extreme of an SHTF situation when escape or rescue for you and your loved ones might well depend on your tires doing their job.
They really are that important, and it’s time to stop pretending that they aren’t.
That’s why in this guy that we are bringing you all the information that you need to know about tires from a prepper’s point of view.
Understanding the basics of tire sizing, type and classification as well as typical repair and maintenance tasks with other information essential for keeping the rubber on the road and you moving down it.
Table of Contents
Tires are the Weak Link in Vehicular Mobility
Rubber tires definitely revolutionized vehicular travel, providing greater adaptation over varying terrain and a dramatically improved ride when it came to noise and quality.
Rubber tires also improved the service life of wheels themselves, serving as a combination cushion and ablative outer layer that prevented wear. It is no understatement to say that modern travel by automobile would look very different, and far worse, without tires.
Accordingly, tires are ubiquitous, Beyond ubiquitous even. Every automobile today with hardly any exceptions utilizes rubber tires.
Every car, truck and van, every motorcycle, every piece of wheeled heavy equipment, everything with a motor. And therein lies the rub if you will pardon the pun. Without tires, or with damaged tires, our modern vehicles are pretty much out of action.
Yes, it is possible to move a vehicle on nothing but the wheels, sans tires, but as anyone who has tried to drive any distance on a totally flat tire will tell you it is rough, rough going. With even a single flat or missing tire control of the vehicle is badly impaired and safety is compromised.
Additionally, damage to the rim of the wheel may result making repair and refit difficult or impossible. These effects get geometrically worse as more tires are degraded or lost to the point that a vehicle is practically immobilized.
In short, no matter how capable your vehicle is, no matter how tall the suspension, how powerful the engine or how much cargo it can carry, if your tires fail the whole operation comes to a grinding, clanking halt.
That means you need to know how to take care of, repair and replace tires on your daily driver and your BOV.
Tire Basics: Understanding Tire Ratings and Classification
Size and Type
Understanding the different classifications for tires will inform you what vehicle they are suitable for. This is denoted by a one or two digit code letter at the beginning or end of the tires sidewall code.
The vehicle classification codes typically encountered are as follows for ISO metric specified tires.
- LT: Light Truck
- ST: Special Trailer
- P: Passenger Car
- T: Temporary, indicating a space saving spare tire or “donut.”
These classifications of tire are further grouped by wheel size, with a given wheel size being further categorized by other factors such as bolt pattern and spacing.
Wheel size is indicated in millimeters or inches, with millimeters being far more common among manufacturers today.
It is worth noting that many consumer oriented publications and advertising will use whichever system of measurement is most common and appealing to the consumers of said vehicles, and this can lead to some confusion.
Wheel size is measured in three dimensions: Diameter, Width and Offset.
The diameter of the wheel measures the surface area of the wheel where the bead of the tire rides. The width is the measurement of the inner distance between each bead and the offset is the distance from the wheel’s true centerline to the mounting surface, usually expressed as half the width measurement above.
Typical consumer grade wheels often feature these measurements in order beginning with the diameter, then the width and lastly the offset but this is not a hard and fast rule.
In a given a category of tire, they will be further grouped by what kind of duty they are intended for, meaning what sort of environments, applications and performance is expected from the tire.
Understanding these classifications can inform you at a glance of what a tire is capable of, and perhaps more importantly, what it is not capable of.
Asking too much of a tire is a great way to accelerate where or even cause an accident in the case of catastrophic failure.
These are the most common tires for passenger vehicles that most consumers will be acquainted with, and drive wheel tires are expected to carry between 550 to 1,100 lbs. Light-medium duty tires for trucks and vans are similar in this performance spectrum, but are expected to carry between 1,100 and 3,300 lb on the drive wheel.
Light-medium duty tires are further differentiated by speed ratings, listed below.
As expected from the name, these tires are designed for high performance, safety and adequate handling in wintry conditions, particularly on snow and ice.
Compared to other light- medium duty tires, these are designed with large voids and gaps between the tread that is designed to increase traction by giving snow, ice and slush room to compact.
Tires in this category that successfully pass winter traction testing are allowed to feature a snowflake design on the sidewall.
Specialized tires in the speed category may feature studs built into the tread that can provide grip even on densely packed snow or solid ice.
Tires of this type are often regulated at the state level as they are quite hard on pavement though notably certain areas mandate them.
Denoted commonly by the above moniker or the letters M+S, for “mud and snow.” Compared to snow tires above, the tread gaps on these tires are smaller and narrower, but compared to standard tires the gaps are larger.
These are a good middle ground for many vehicles that might have to periodically deal with inclement weather, and are greatly preferred by many drivers because they are significantly quieter than snow tires which are notoriously noisy.
These tires are intended to have responsive, reliable and easy handling on roads and highways while maintaining adequate traction and performance off-road in the bargain.
In addition, they typically perform above average through snow and ice. An excellent all-around choice for many drivers. Compared to all season tires they might be a little noisy.
These tires fear deep, open, knobby tread and are intended to provide the best traction, response and handling in mud and other inclement terrain conditions, but fare pretty poorly on Pavement compared to other tires in this category.
Notoriously noisy, and might be a liability if emergency maneuvering is required on the pavement.
These tires are rated for both durability and handling at the highest speeds achievable by vehicles in this class, up to 168 mph for high performance tires, and up to 186 mph for ultra high performance tires.
As you might expect, these are not renowned for durability or ride characteristics, often described as harsh.
A special category of tire that is capable of maintaining a modicum of its performance envelope at a reduced speed in the event of a total loss of air pressure.
Stiff sidewalls maintain the shape of the tire and prevent damage to the rim of the wheel. Tires of this type are typically installed on vehicles which do not carry a spare tire. Notably, some may not be repaired if damaged.
For super-high performance vehicles, race car tires are employed, and are designed to maximize performance handling characteristics of the vehicle at the expense of durability and longevity. Available in three subtypes, slick, rain and DOT (street legal) race car tires.
For large trucks and similar vehicles that provide service on the roads and highways, heavy duty tires are employed and carry a load of 4,000 to 5,500 lbs on the drive wheels. Commonly seen mounted in tandem, or two to a side, on drive axles.
A subcategory of heavy duty tire typically used on agricultural equipment, construction vehicles and other large and heavy working machines that move around on soft terrain that might be uneven or loose.
Still commonly employed at hard surfaced workspaces like ports, factories, airports and so forth. Tires of this type feature the stereotypical wide and deep, v-shaped tread.
This covers the gamut of tires that most preppers are likely to encounter or require in the course of their lives.
As you can imagine, many, many other kinds of tires abound, from tiny bicycle and lawn equipment tires to aircraft tires capable of handling the enormous stresses and friction generated on landing.
Putting it All Together
A fundamental understanding of the above will allow you to quickly and easily decipher the long alphanumeric code on typically found on the sidewall of a tire or in manufacturer’s literature. A typical tire code could look like the following:
P215/65R15 95H M+S
In this case, the code indicates the following, listed from left to right:
P: Passenger Car, a tire for standard passenger vehicles.
215: Width, in millimeters. From side wall to side wall.
65: Separated by the slash, indicates aspect ratio of sidewall height.
R: Indicates a radial tire. Could be D for diagonal or B for bias belt. No letter in this position indicates a cross-ply tire type.
15: Diameter of wheel this tire is designed to fit, in inches. Occasionally seen in millimeters, and shown as a three digit number.
95: Load index number. Cross referencing this on the ETRTO standards table will reveal the load rating of the tire. In this case, 1,520 lbs.
H: The speed rating of the tire, sometimes seen earlier in the sequence before or after the aspect ratio.
M+S: Short for “Mud and Snow”; an All-Season tire type.
Though the long strings of characters might appear baffling to the uninitiated at first, understanding the code is quite simple and with just a little bit of study you’ll soon have the only relevant tables memorized in the case of load indexes and speed ratings.
Common Tire Failure Events
We ask a lot from our tires, and through a combination of wear, abuse and incidental damage from road hazards or a loss of traction they occasionally fail, and dimes to dollars it will always happen when we can least afford it, either for our timetable or our pocketbook.
Understanding common tire failure events will help better inform your decision to attempt to save the tire or ditch it and get on with your life.
If the tire can be saved, the type of failure will further dictate what repair procedures and remedial action is required.
The most common tire failure event is the flat. A tire goes flat because it can no longer hold a volume of air required to inflate it.
A leak can be slow or fast, and assuming the tire is not old, neglected and in bad repair is usually caused by debris on the roadway or by striking something with the tire.
When enough air pressure is lost, the tire begins to collapse causing undesirable handling characteristics or potentially even a loss of control.
Then you have other, how shall we say, more dramatic tire failure events. Catastrophic failures (blowouts) result in either the tire coming off of the wheel entirely or, more likely, disintegrating as a result of severe damage, typically in conjunction with an older or worn tire.
A catastrophic tire failure, unfortunately, happens most often when the car is in motion and typically at high speed. If you have ever seen a severe blowout traveling on the highway or interstate, you know what a catastrophic tire failure looks like and how scary it can be.
Pieces of the tire come off and fly in every direction, or perhaps the mostly intact tire itself. The unfortunate vehicle that lost the tire usually swerves from side to side and, sometimes and particularly in the case of larger vehicles, loses control entirely.
It is difficult to predict, if at all possible, when a catastrophic blowout will happen, but you must mentally prepare for them so that you do not panic, and overcorrect as that will certainly cause a crash.
However, if you are fortunate, you will go to get in your vehicle one day under any circumstances and notice that a tire has simply gone flat. This is decidedly aggravating, what give thanks that it did not go flat while you were behind the wheel going down the road.
Repairing or Replacing a Damaged Tire
So let’s say you have a flat tire. That’s a major pain, but not the end of the world. If you have a spare tire on hand and the items required to jack up the car and remove the wheel with the flat you can get back in business and just about 15 minutes once you have a little practice.
But then later on you’ll have to assess the flat tire for damage and determine whether or not you can make a meaningful repair. Tires that go flat from puncture damage generally in one of two ways.
A penetration through the trade or a penetration through the sidewall. A penetration through the tread is serious, but usually user repairable, at least in the short term.
A sidewall penetration is another story and, without specialized equipment and some skill, repairable only for a very short-term, low demand drive if at all. A serious sidewall penetration destroys the tire.
Repairing a Damaged Tire
Should your tire become punctured, you’ll need to attempt a repair if you want to save it and get it back in operation.
As a rule, punctures through the tread area are generally use a repairable and you might not even have to remove the wheel in order to do so.
However, sidewall punctures almost invariably require removing the wheel and dismounting the tire in order to even attempt repair, the repair is usually not possible.
The following methods are used to repair punctures.
Plug: A plug style repair consists of a length of sticky, epoxy coated rubber material that is forced through the hole present in the tread area of a tire.
These kits are commonly available, and usually consist of a couple of T-handled tools suitable for reaming out and cleaning up the puncture hole and inserting the plug, along with a knife or cutter to cleanly cut off the exposed insert when finished.
Although rated for temporary use at slower speeds, plugs may prove to be suitable for keeping a tire in operation for quite a distance if the damage is not severe.
Patch: a patch is similar in composition to a plug, generally consisting of a rubberized or synthetic patch of material along with epoxy or other specialized adhesives to adhere it to the tire.
For repairs in the tread area, patches are applied with the tire dismounted from the wheel. This makes them less suitable for roadside repairs except in very specific circumstances, notably attempting to repair a small, uniform puncture through a sidewall when applicable.
Combination: for maximum repair longevity and strength a plug and patch might be used in combination when it can be done.
Assuming the damage to the tire is not too severe and the overall health of the tire is good this can get a tire back in operation for a long time before you need to take it to a garage for proper assessment.
Although the makers of such products will be quick to advise you that their repair kits are temporary solutions there are many seasoned drivers, particularly off-roaders, who have permanently repaired their own tires with no ill effects using a combination patch and plug.
Replacing a Damaged Tire
For vehicles that carry a spare tire I need to replace a flat tire on the roadside, or if you are fortunate enough to have a spare tire at your base or in your garage, the easiest way to get a vehicle rolling again after suffering a flat is simply to replace it and deal with the damaged tire later.
This is one of the most fundamental emergency tasks that a driver learns at the beginning of their driving career, and one that you’ll have cause to practice whether you want to or not.
Unfortunately our roadways are chock full of many hazards, and even the most cautious driver cannot see every loose nail or jagged piece of rebar.
Changing out a tire is a simple process, but it might not be easy. Having the right tools makes all the difference, check out the list below.
Disclosure: This post has links to 3rd party websites, so I may get a commission if you buy through those links. See my full disclosure for more.
Jack: this is standard issue for most modern automobiles, and has been for decades. You will place the jack to lift up the vehicle at the designated lifting point closest to the tire that has gone flat.
Note that most included vehicle jacks are small, fiddly and comparatively weak, and you should never, ever get underneath a vehicle that is held up only by a jack.
If you have room for it in your vehicle, a full size floor jack is a good inclusion, and you should definitely have one at home in your garage.
Jack Stands: jack stands are simple and extremely sturdy devices used to prop up a lifted vehicle with greater assurance and safety.
Rarely used for a roadside tire change, they can nonetheless provide a greater margin for error and added stability for the task if you have room to include them in your vehicle. If not, make sure you have a set at home in the garage.
Lug Nut Wrench: a lug nut wrench or socket is sized to fit the lug nuts of your specific vehicle. You might use the included lug nut wrench your vehicle came with, or upgrade to a nicer model to make the task a little easier.
Lug nuts can be extremely stubborn and difficult to remove, even when cranking on the wrench with your full body weight so they are often used with a…
Breaker Bar: an extension bar that will slip over your lug nut wrench or a one piece, extra long lug nut wrench. Intended to provide the necessary leverage to easily break loose stuck and troublesome lug nuts. For the most stubborn lug nuts this might make the difference between a successful emergency tire change or being stuck in a major pickle.
Spare Tire: most vehicles carry a spare tire, or more properly a spare wheel fitted with a pre-inflated tire so you can change out the wheel entirely and then deal with the flat tire later on.
Depending on the vehicle, this might be a one-to-one replacement, or full size spare, or it might be a compact spare tire, for temporary usage and commonly called a donut.
Either conserve to get you back on the road and off the shoulder, but you must know that small, temporary spare tires are usually limited in both the distance that they may travel and the speed they are rated for.
Gloves: changing a tire is going to cover your hands with dirt, soot and grease, and provide ample opportunity for busted or skinned knuckles. Make sure you include a good, lightweight set of work gloves as part of your vehicle’s emergency equipment compliment.
Tire Changing Steps
We know what tools are needed, now it is time to get down to business.
Step #1: Your first objective is to safely move the vehicle somewhere that you can safely change the tire, if it is still mobile. Ideally this is a place well away from any road traffic on flat, hard ground that will support the jack.
Trying to jack up a car on soft ground generally will not work, and then you’ll need to support the jack with something wide and hard to bear the load.
Step #2: Next, attach the jack to the jack point closest to the flat tire as indicated by the manual, and begin jacking up the car.
Note that you must only lift the car up just enough where the tire is off the ground, and no more. Raising the car higher than necessary will only destabilize it while on the jack and increase the consequences should the Jack slip.
Step #3: Now, grab your lug nut wrench and attach the breaker bar if necessary. Begin loosening the lug nuts until you can unscrew them by hand easily. Remove all of the lug nuts, then pull off the tire.
Step #4: Now retrieve the spare tire. Double check to ensure that it is properly inflated before you mount it. Seat the tire all the way on the bolts and then hold it in place while you hand tighten each lug nut until just snug.
Step #5: Begin tightening the lug nuts, using an alternating pattern as specified by the manual, or lacking the prescribed method tighten one nut a little bit before going to its opposite number in a clockwise direction, tightening each the same amount until they are all torqued down hard.
Step #6: Lower the car gently, remove the jack, stow your tools and drive away.
That’s it, there is not much to it, and assuming you have a little bit of practice you can usually complete this ordeal in just about 15 minutes, maybe a little less if conditions permit.
Speaking of that, you should practice changing the wheels on your car a few times so that you’ll be confident and fluent even in bad conditions.
Most people rarely think about their tires unless something goes wrong, but for preppers, it is definitely time to start thinking about them since we will depend on them so very much.
You should learn to assess your tires and deal with damage just like any other problem you could reasonably expect to encounter in a survival situation.
Additionally, a thorough understanding of tire manufacture and codes will help greatly when you need to source or scavenge your own tires.